Grain-size-dependent microstructure effects on cyclic deformation mechanisms in CoCrFeMnNi high-entropy-alloys

2022 ◽  
Vol 210 ◽  
pp. 114459
Author(s):  
Mao-Yuan Luo ◽  
Tu-Ngoc Lam ◽  
Pei-Te Wang ◽  
Nien-Ti Tsou ◽  
Yao-Jen Chang ◽  
...  
Keyword(s):  
Grain Size ◽  
Cyclic Deformation ◽  
Deformation Mechanisms ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Size Dependent ◽  
Microstructure Effects

scholarly journals Al, Cu and Zr Addition to High Entropy Alloys: The Effect on Recrystallization Temperature

2018 ◽  
Vol 941 ◽  
pp. 1137-1142
Author(s):  
Elena Colombini ◽  
Andrea Garzoni ◽  
Roberto Giovanardi ◽  
Paolo Veronesi ◽  
Angelo Casagrande
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Single Phase ◽  
Boundary Energy ◽  
Cold Deformation ◽  
Recrystallization Temperature ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Ni Alloy ◽  
Sluggish Diffusion

The equimolar Cr, Mn, Fe, Co and Ni alloy, first produced in 2004, was unexpectedly found to be single-phase. Consequently, a new concept of materials was developed: high entropy alloys (HEA) forming a single solid-solution with a near equiatomic composition of the constituting elements. In this study, an equimolar CoCrFeMnNi HEA was modified by the addition of 5 at% of either Al, Cu or Zr. The cold-rolled alloys were annealed for 30 minutes at high temperature to investigate the recrystallization kinetics. The evolution of the grain boundary and the grain size were investigated, from the as-cast to the recrystallized state. Results show that the recrystallized single phase FCC structures exhibits different twin grains density, grain size and recrystallization temperatures as a function of the at.% of modifier alloying elements added. In comparison to the equimolar CoCrFeMnNi, the addition of modifier elements increases significantly the recrystallization temperature after cold deformation. The sluggish diffusion (typical of HEA alloys), the presence of a solute in solid solution as well as the low twin boundary energy are responsible for the lower driving force for recrystallization.

Effects of Mn Content and Grain Size on Hydrogen Embrittlement Susceptibility of Face-Centered Cubic High-Entropy Alloys

2020 ◽  
Vol 51 (11) ◽  
pp. 5612-5616
Author(s):  
Motomichi Koyama ◽  
Haoyu Wang ◽  
Virendra Kumar Verma ◽  
Kaneaki Tsuzaki ◽  
Eiji Akiyama
Keyword(s):  
Grain Size ◽  
Hydrogen Embrittlement ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Mn Content ◽  
Face Centered

scholarly journals Real-time nanoscale observation of deformation mechanisms in CrCoNi-based medium- to high-entropy alloys at cryogenic temperatures

2019 ◽  
Vol 25 ◽  
pp. 21-27 ◽  
Author(s):  
Qingqing Ding ◽  
Xiaoqian Fu ◽  
Dengke Chen ◽  
Hongbin Bei ◽  
Bernd Gludovatz ◽  
...  
Keyword(s):  
Real Time ◽  
Deformation Mechanisms ◽  
High Entropy Alloys ◽  
Cryogenic Temperatures ◽  
High Entropy

scholarly journals Microstructure and composition dependence of mechanical characteristics of nanoimprinted AlCoCrFeNi high-entropy alloys

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dinh-Quan Doan ◽  
Te-Hua Fang ◽  
Tao-Hsing Chen
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Twin Boundary ◽  
Deformation Mechanism ◽  
Alloy Composition ◽  
Elastic Recovery ◽  
Local Stress ◽  
High Entropy Alloys ◽  
Polycrystalline Structure ◽  
High Entropy

AbstractMolecular dynamics is applied to explore the deformation mechanism and crystal structure development of the AlCoCrFeNi high-entropy alloys under nanoimprinting. The influences of crystal structure, alloy composition, grain size, and twin boundary distance on the mechanical properties are carefully analyzed. The imprinting load indicates that the highest loading force is in ascending order with polycrystalline, nano-twinned (NT) polycrystalline, and monocrystalline. The change in alloy composition suggests that the imprinting force increases as the Al content in the alloy increases. The reverse Hall–Petch relation found for the polycrystalline structure, while the Hall–Petch and reverse Hall–Petch relations are discovered in the NT-polycrystalline, which is due to the interactions between the dislocations and grain/twin boundaries (GBs/TBs). The deformation behavior shows that shear strain and local stress are concentrated not only around the punch but also on GBs and adjacent to GBs. The slide and twist of the GBs play a major in controlling the deformation mechanism of polycrystalline structure. The twin boundary migrations are detected during the nanoimprinting of the NT-polycrystalline. Furthermore, the elastic recovery of material is insensitive to changes in alloy composition and grain size, and the formability of the pattern is higher with a decrease in TB distance.

Sign in / Sign up

Export Citation Format

Share Document